Stepbrothers In Love (Yuumika) Owari No Seraph

Mikaela is a 16 year old boy that crossdresses. He get adopted and gets a new brother named Yuichiro. Yuchiro and Mikaela goes to the same school but Yuichiro likes Mikaela cause he thinks Mikaela is a girl so when they become siblings, he find out that his crush is the same sex